fix dns #174

Job	Run time
Debug build	23s
Debug build (Go 1.21)	27s
Debug build (Go 1.20)	34s
cross (windows-amd64, windows, amd64, v1)	47s
cross (windows-amd64-v3, windows, amd64, v3)	50s
cross (windows-386, windows, 386)	43s
cross (windows-arm64, windows, arm64)	43s
cross (windows-arm32v7, windows, arm, 7)	46s
cross (linux-amd64, linux, amd64, v1)	50s
cross (linux-amd64-v3, linux, amd64, v3)	52s
cross (linux-386, linux, 386)	49s
cross (linux-arm64, linux, arm64)	50s
cross (linux-armv5, linux, arm, 5)	50s
cross (linux-armv6, linux, arm, 6)	51s
cross (linux-armv7, linux, arm, 7)	48s
cross (linux-mips-softfloat, linux, mips, softfloat)	51s
cross (linux-mips-hardfloat, linux, mips, hardfloat)	54s
cross (linux-mipsel-softfloat, linux, mipsle, softfloat)	47s
cross (linux-mipsel-hardfloat, linux, mipsle, hardfloat)	44s
cross (linux-mips64, linux, mips64)	47s
cross (linux-mips64el, linux, mips64le)	44s
cross (linux-s390x, linux, s390x)	49s
cross (darwin-amd64, darwin, amd64, v1)	58s
cross (darwin-amd64-v3, darwin, amd64, v3)	1m 2s
cross (darwin-arm64, darwin, arm64)	50s
cross (freebsd-amd64, freebsd, amd64, v1)	57s
cross (freebsd-amd64-v3, freebsd, amd64, v3)	52s
cross (freebsd-386, freebsd, 386)	49s
cross (freebsd-arm64, freebsd, arm64)	46s
	22m 53s

Provide feedback